In electromagnetic simulation and analysis, network models are often utilized for analyzing electrical components, circuits, and systems. Network models may be characterized by network parameters, such as impedance parameters and scattering parameters (S-parameters).
S-parameters are often represented in matrix form and associated with reference impedance. The reference impedance is often set to be 50 Ohms (Ω), partly because the characteristic impedance of typical signal transmission line systems is around 50Ω. However, for systems with power/ground lines, the effective input impedance is typically much smaller than 50Ω. Therefore, S-parameters generated using 50Ω reference impedance may be insensitive to the variation of electrical properties of power/ground systems.
Accordingly, there is a need for a system and method for adapting reference impedance in order to improve accuracy in electromagnetic simulation and modeling.